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A. NI. ALEXANDER.

SKIVING KNIFE.

APPL|CAT|0N FILED SEPT. e. 19|4.

Patented June 3, 1919.

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narnnr ALEXANDER M. ALEXANDER, OF BEVERLY, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OE NEW JERSEY.

SKIVINGr-KNIFE.

To all whom t may concern:

Be it known that I, ALEXANDER M. ALEX- ANDER, a citizen of the United States, resid ing at Beverly, in the county of Essex and. State of Massachusetts, have invented certain new and useful Improvements in Skiving-Knives; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to cylindrical knives employed for skiving leather and analogous material and more particularly to cylindrical band knives of this general type.

This type of knife is subjected to constant and hard usage and in consequence is worn away rapidly and must be replaced at frequent intervals. In view' of this it is advisable to employ a knife which may be manufactured at a minimum initial cost and replaced with facility when worn out. These advantages vare embodied in' a band knife which is clamped to a cylindrical holder and which may be adjusted to compensate for wear of the cutting edge. It is customary in the manufacture of skiving knives of this type to form the knife blade of a thin sheet of tempered steel bent into a substantially cylindrical shape and having an outer beveled cutting face. This knife blade only approximates a true cylinder, but as it has a certain degree of flexibility the inequalities in the shape may be substantially overcome by clamping the knife rigidlyto a true holder which supports the knife blade externally and causes it to assume a substantially true cylindrical form. In addition to the inaccuracies in the shape of the knife however it also varies slightly `in thickness throughout different portions of the circumference and although the outer surface of the knife may be substantially true, the inner surface of the knife and the cutting edge vary slightly owing to the inequalities in the thicknesss and as the knife is rotated at a comparatively high speed these slight inaccuracies in the cutting edge impair the quality of the work produced.

The object of the present invention is to provide a knife of this type which enables a true cylindrical cutting edge to be perma- Specication of Letters Patent.

Patented June 3, 1919.

Application led September 8, 1914. Serial No. 860,737.

nently maintained and which may be adjusted with facility as the knife edge is ground away. To this end a feature of the invention comprises a cylindrical band knife having a beveled outer cutting face, an internal holder having a true cylindrical face engaging with the inner surface of the band knife, and a band wrapped about the blade and capable of being contracted to clamp the blade to the holder.

Still further features of the invention consist in certain novel features of construction, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

In the accompanying drawings illustrating the preferred form of the invention; Figure l represents a side elevation partly in section of a skiving knife embodying the several features of the invention; Fig. 2 is a front elevation of the knife shown in Fig. l; Fig. 3 is a detail showing a section of the blade clamping mechanism and means f 'for connecting it to the knife holder; and

Fig. 4 is a detail illustrating a side elevation of the clamping mechanism shown in Fig. 3.

As stated previously, the knife blade is beveled upon the outer face to form the cutting edge which is located at the inner face of the knife, and with this construction the cutting edge will vary from a true cylinder according to the variations in thickness of the knife blade. These variations are slight, but are nevertheless objectionable in operating upon the ner grades of work where extreme accuracy is required. In order to obviate these objections and permit a true cutting edge to be obtained without increasing the expense yof manufacture of the knife blade, the present invention contemplates the provi-sion of an internal knife holder having a true cylindrical knife engaging surface and an external clamping mechanism for securely clamping the knife blade to the holder. To this end a knife holder 1 is rotatably mounted upon a hollow bearing 2 and an anti-friction bushing 3 is inter. posed between the holder and bearing and secured to the holder in any suitable manner. The knife holder l is provided with a knife engaging surface 5 which is machined or groundn any suitable manner to present a true cylindrical surface of rotation to the interior of the knife blade. The knife blade 6 is formed in the usual manner of a band of steel bent to a substantially cylindrical shape to form `a tubular knifeV blade and secured to the holder by an external clamping ring or band Syrengaging with the knife blade immediately opposite u the knife engaging surface 5 of the holder. The knife holder is 4conveniently rotated by a grooved pulley 10 Which is secured to thev holder by one or more set screwsr 11. The clamping band 8 is positioned in the proper relation to the knife blade and contracted to clamp the knife blade to the holder by' a pair of arms 13 and 14 connected to the opposite ends of. the clamping band. 4The arm'13 is rigidly connected to one end ofthe clamping band and is provided with `a depending lip'` 15 having an outwardly upturned portion which engages beneath an annular flange 16 Y formed upon the face of the drive pulley 10, as shown clearly in Fig. 3. The connection betvveenthe arin' 13 and the pulley 10 serves to position the clamping band in the proper relation to the knife blade. The clamping band is contracted by `drawing the two' ends of the band toward one another and this is conveniently accomplished by pivoting the arm 14 upon the arm.13 atl 25 and providing a locking lever 17 fulcrumed at 18 upon the arI'n 13v and operatively engaging with a curved face 19 Aformed upon the arm 14 to. rock the ends ofthe arms 13 and 14 together as the locking lever 17 is swungoutwardly. The operative connection between' the locking lever 17 and the arm14 is secured by a lip 20 secured to the lever and projecting overthe face of the arm, asV shown clearly in 4. The portion of the band diametric'ally `opposite the ends' isV positioned in a similar manner by an arm 21 secured thereto and having its end operatively engaging with the flange 16. It Will be noted that Withythis construction the entire interior of the knife is free from encumbrances and forms a throat or passage through Which vchips and other Waste material may be convenientlyl ejected from the knife. It Will be further noted that with the provision of the enternal. clamping and adjusting rings upon the outsideJ of the holder the various adjustments ofthe knife and the removal thereof may be effected readily from the outside.

It vvill be noted from an inspection of the dravvings that the knife holder is provided with a true cylindrical blade engaging surface and vvith a recessed portion `back of the edly connected an annular adjusting ring 23. The ring 'serves to adjust and to retain in adjusted position the knife blade and is connected to the blade'through the usual form of pin and slot connections indicated;` yat 24.

While it is preferred to employ the specific construction and arrangement of parts shown and described, it Will be understood that this construction and arrangement is not essential except so far as specified Vin the claims, and may be changed or modified Without departing from the broader features of the invention.

The invention having been described, what is claimed is:

1. A skiving knife, having in combination, an internal knife holder having a true cylindrical blade engaging surface, a thin tubular knife blade surroundin the holder and sufficiently flexible to conform to the holder, a clamping band Wrapped about the outside of the blade and sufficiently flexible at every point in its length to conform toithe knife blade, and means for contracting the band to clamp the blade to the holder. 2. A skiving knife, having in combination, a holder, a cylindrical band knife, a Y

Vthe ring,and means for actuating the members to draw the ends of the ring together and clamp the knife to the holder.

3. A skiving knife, having in combination, a hollovsr bearing, a holder rotatably supported upon the bearing, a cylindrical knife surrounding the holder, and means for clamping the knife to the holder.

4. A 'skiving knife,lhaving in combination, a holder, a cylindrical knife surrounding the holder, an yadjusting ring operatively connected to the knifeV and threadedly mounted upon the holder, and means for clamping the knife to the holder.

A skiving knife, having in combination, la holder, a cylindricalV knife, a ring for clamping the knife to the holder, and operative connections betvveen the ring and holder to positiongthe ring properly with relation to the knife. I

6. A skiving knife, having .in combination, a holder, a drive pulley secured to the holder, a cylindricalvknife supported upon the holder, and an adjusting ring connected to the knife and threadedly. mounted upon knife. blade engagingV surface to which is threadf n 8. A vskiving knife, having in comb-ination, ak holder, a knife supported upon the holder, aclamping ring surroundinglv the knife, a pair of arms pivoted together and connected `at one end'to opposite ends f the ring, and means for 'drav'ving the vfree vends lou of the levers together to contract the ring and clamp the knife to the holder.

9. A skiving knife, comprising a clamping ring, an arm .secured to one end of the ring, a second arm pivoted upon the first mentioned arm and operatively connected to the opposite end of the ring, and a locking lever pivoted tothe first mentioned arm and operatively connected With the free end of the second arm to draw the two ends of the ring together upon an outward movement of the lever.

10. A skiving knife, having in combination, an internal holder, -a tubular band knife supported externally of the holder, a clamping member surrounding. the band knife, means for contracting the member to clamp the knife to the holder, and means for adjusting the knife axially of the holder.

11. A skiving knife, having in combina tion, an internal holder, a tubular band knife supported externally `of the holder, a

surface, a tubular lmife blade supported eX- ternally of the holder, a rotary adjusting ring connected to the knife blade and positioned in the recessed portion of the holder, and a clamping member engaging exterior-ly With the knife blade opposite the blade engagi-ng surface of the holder to clamp the knife blade to the holder.

ALEXANDER M. ALEXANDER.

Witnesses CHESTER E. ROGERS, LILLIAN B. DUTEE.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

